Receivable from Mutual Funds, Insurance Companies, and Other - Composition of Partnership's Receivable from Mutual Funds, Insurance Companies and Other (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Brokers And Dealers [Abstract]
Asset-based fees from mutual fund and insurance companies	$ 211	$ 200
Deposit for Canadian retirement accounts	187	189
Fees for shareholder accounting services	52	48
Total	$ 450	$ 437